Fighting to exist

The more closely related two species are, the more they're apt to drive one another to extinction.

By Jef Akst | June 14, 2011

Lin Jiang displays a microscope image of a protist species used in the experimental microcosmsGEORGIA TECH / GARY MEEK

A new study published today (June 14) in Ecology Letters provides experimental evidence for a an assumption of evolutionary biology accepted since Darwin first proposed it in 1859's On the Origin of Species—that competition is greater among closely related species. Researchers at Georgia Tech established 165 experimental microcosms—simplified, laboratory ecosystems—harboring either one or two species of ciliated protists along with three varieties of bacterial prey species. Weekly, the team documented the abundance of each species in each microcosm, and found that after 10 weeks, all individually housed protists species survived. But in more than half of the arenas containing two protist species, one species had grown to dominate the population, driving the other to extinction.

The competition was fiercer when the two species in the microcosm were more closely related. "We found that species extinction occurred more frequently and more rapidly between species of microorganisms that were more closely related," Georgia Tech's Lin Jiang said in a press release. "This study is one step toward a better understanding of how phylogenetic relatedness influences species interactions."

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Anonymous

June 14, 2011

Is this the opposite of symbiogenesis? What I've been reading about is gene swapping for antimicrobial resistance that exemplifies social selection. Does social selection then direct mechanisms of natural selection?

DUH!but give me the same amount of money and I can show humans can be taught to work in harmony to a point. OR read what people do in theface of tragedies. Or read the stories of animals which defy this trait to dominate.

the relatedness is related to difference.Â If the closest relative to a carnivore was by sheer chance an herbivore, there would be less niche overlap and less competition, leading to not the same results as found in this study. In my work area, The imported fire ant has driven the related tropical fire ant to local extinction but hasn't done this to more closely related species in its native homeland.Â It is nice the paper has found a nice microbial example of our story line about Homo sapiens and Neanderthals.

Thanks for the added perspective, Rich. Indeed, it is difficult for me to compare genetic relatedness across species of bacteria that seem to be swapping genes for antimicrobial resistance. But the assumption can be made that gram positive cocci like MRSA are not closely related to the gram negative rods, ESBLs that are swapping genes. Symbiogenesis might therefore be beneficial to at least one of the two organisms, if not benefical to both.

Is this the opposite of symbiogenesis? What I've been reading about is gene swapping for antimicrobial resistance that exemplifies social selection. Does social selection then direct mechanisms of natural selection?

DUH!but give me the same amount of money and I can show humans can be taught to work in harmony to a point. OR read what people do in theface of tragedies. Or read the stories of animals which defy this trait to dominate.

the relatedness is related to difference.Â If the closest relative to a carnivore was by sheer chance an herbivore, there would be less niche overlap and less competition, leading to not the same results as found in this study. In my work area, The imported fire ant has driven the related tropical fire ant to local extinction but hasn't done this to more closely related species in its native homeland.Â It is nice the paper has found a nice microbial example of our story line about Homo sapiens and Neanderthals.

Thanks for the added perspective, Rich. Indeed, it is difficult for me to compare genetic relatedness across species of bacteria that seem to be swapping genes for antimicrobial resistance. But the assumption can be made that gram positive cocci like MRSA are not closely related to the gram negative rods, ESBLs that are swapping genes. Symbiogenesis might therefore be beneficial to at least one of the two organisms, if not benefical to both.

Is this the opposite of symbiogenesis? What I've been reading about is gene swapping for antimicrobial resistance that exemplifies social selection. Does social selection then direct mechanisms of natural selection?

DUH!but give me the same amount of money and I can show humans can be taught to work in harmony to a point. OR read what people do in theface of tragedies. Or read the stories of animals which defy this trait to dominate.

the relatedness is related to difference.Â If the closest relative to a carnivore was by sheer chance an herbivore, there would be less niche overlap and less competition, leading to not the same results as found in this study. In my work area, The imported fire ant has driven the related tropical fire ant to local extinction but hasn't done this to more closely related species in its native homeland.Â It is nice the paper has found a nice microbial example of our story line about Homo sapiens and Neanderthals.

Thanks for the added perspective, Rich. Indeed, it is difficult for me to compare genetic relatedness across species of bacteria that seem to be swapping genes for antimicrobial resistance. But the assumption can be made that gram positive cocci like MRSA are not closely related to the gram negative rods, ESBLs that are swapping genes. Symbiogenesis might therefore be beneficial to at least one of the two organisms, if not benefical to both.

There is new in this research.this we experiences everyday..We hate our nearest relative or neighbour strongly than distant rich man. Simple reason is if our neighbourÂ got success heÂ overcome the fear of death Iam near to death.Close relationship increase hate, fear stromngly than the distant relationshipÂ

There is new in this research.this we experiences everyday..We hate our nearest relative or neighbour strongly than distant rich man. Simple reason is if our neighbourÂ got success heÂ overcome the fear of death Iam near to death.Close relationship increase hate, fear stromngly than the distant relationshipÂ

There is new in this research.this we experiences everyday..We hate our nearest relative or neighbour strongly than distant rich man. Simple reason is if our neighbourÂ got success heÂ overcome the fear of death Iam near to death.Close relationship increase hate, fear stromngly than the distant relationshipÂ

I suspect that some of the commenters didn't understand what the article was saying. The study compared protists, not bacteria, which don't share DNA unless they're close enough to interbreed, which is another way of eliminating competitors. Â And if they are closely related, supposedly they have similar environmental and nutritional requirements, but if one protist species is slightly less apt at acquiring these requirements under circumstances where these resources are limited, then the less able species will be expected to go extinct. Â The members of the dominant species who are less able to acquire those requirements will also disappear while their more able brethren will reproduce.

I suspect that some of the commenters didn't understand what the article was saying. The study compared protists, not bacteria, which don't share DNA unless they're close enough to interbreed, which is another way of eliminating competitors. Â And if they are closely related, supposedly they have similar environmental and nutritional requirements, but if one protist species is slightly less apt at acquiring these requirements under circumstances where these resources are limited, then the less able species will be expected to go extinct. Â The members of the dominant species who are less able to acquire those requirements will also disappear while their more able brethren will reproduce.

I suspect that some of the commenters didn't understand what the article was saying. The study compared protists, not bacteria, which don't share DNA unless they're close enough to interbreed, which is another way of eliminating competitors. Â And if they are closely related, supposedly they have similar environmental and nutritional requirements, but if one protist species is slightly less apt at acquiring these requirements under circumstances where these resources are limited, then the less able species will be expected to go extinct. Â The members of the dominant species who are less able to acquire those requirements will also disappear while their more able brethren will reproduce.